New research confirms what health authorities have long advised. There is no safe level of drinking and cannabis use in pregnancy. Growing evidence now links both substances to serious, lasting harm for mother and baby. Yet hundreds of thousands of pregnancies in the United States involve exposure to one or both every year.

The figures are striking. Data from the National Survey on Drug Use and Health (NSDUH) show that between 13% and 14% of pregnant women drank alcohol in the past 30 days. Around 5% reported binge drinking. That translates to roughly 485,000 pregnancies annually with alcohol exposure. Cannabis use is rising fast too. In 2017, 4.2% of pregnant women self-reported marijuana use. By 2021 to 2023, that figure had climbed to 6.8%, with the highest rates in the first trimester.

What Alcohol Does to a Developing Baby

Alcohol crosses the placenta quickly. A developing foetus cannot metabolise it effectively. Exposure can therefore persist during the most critical windows of brain and organ development.

The consequences can be profound and lifelong. Foetal alcohol spectrum disorders (FASD) cover a wide range of conditions. These include growth restriction, structural abnormalities, and neurodevelopmental impairment affecting cognition, attention, behaviour, and executive function. Many affected individuals never display the classic facial features linked to the condition. Doctors therefore miss and underdiagnose FASD far too often.

Binge drinking carries the greatest risk. It raises the odds of miscarriage, stillbirth, and preterm birth significantly. The Centers for Disease Control and Prevention (CDC) and the American College of Obstetricians and Gynecologists (ACOG) are unambiguous: no amount, timing, or type of alcohol is safe in pregnancy.

Drinking and Cannabis in Pregnancy: What the Research Shows

The evidence on alcohol has built up over decades. The science on prenatal cannabis use is newer, but it is moving quickly. And the picture it paints is a worrying one.

Multiple large studies and meta-analyses now link alcohol and cannabis use during pregnancy to low birth weight, preterm birth, and neonatal intensive care unit admission. In some cases, researchers also record perinatal mortality. A study published in JAMA Pediatrics confirmed these associations even after researchers accounted for co-use of tobacco products. Cannabis appears to be an independent risk factor, not merely a sign of other risky behaviours.

The risks do not stop at birth. Children whose mothers used cannabis in pregnancy show higher rates of anxiety, aggression, and hyperactivity. They also carry elevated levels of cortisol, the body’s primary stress hormone. Genetic analysis of placental tissue further revealed lower expression of key immune-activating genes in these children, including the pro-inflammatory cytokines that help fight dangerous infections.

Yasmin Hurd, PhD, director of the Addiction Institute at Mount Sinai Medical Center, put it plainly. “Pregnant women are being bombarded with misinformation that cannabis is of no risk,” she said. “The reality is that cannabis is more potent today than even a few years ago. Our findings indicate that using it during pregnancy can have a long-term impact on children.”

Separate research links prenatal cannabis use to gestational hypertension, preeclampsia, and placental abruption. The risks extend to the mother as well as the baby.

When You Combine Substances, the Risks Multiply

Among pregnant women who drank alcohol, more than one third also used at least one other substance. Tobacco and cannabis were the most common. Studies on combined cannabis and nicotine exposure found notably higher rates of maternal and neonatal complications, including infant death, compared to either substance alone.

This compounding effect worries researchers and clinicians in equal measure. Many women may not yet know they are pregnant during the first trimester, which is precisely when these exposures can do the most harm.

Alcohol and Cannabis During Pregnancy Do Not Become Safe During Breastfeeding

Many mothers assume the risk ends once the baby arrives. It does not. THC and other cannabinoids appear in human breast milk. Concentrations stay elevated throughout a day of repeated use. Newborns are especially vulnerable. Their metabolism and kidney function are still immature. They cannot break down and excrete chemical compounds the way adults can. A breastfeeding mother who uses cannabis more frequently exposes her baby to more of it, directly.

A Worrying Gap in Awareness and Care

The CDC data expose another layer of the problem. As many as 17.8% of pregnant women who currently drank alcohol had no healthcare provider at all. On top of that, 27.4% of drinkers in pregnancy reported frequent mental distress. Substance use in this group often connects to broader struggles around mental health and access to services.

Public health bodies call for universal, nonjudgmental screening as part of routine antenatal care. Women need accessible pathways to support, not stigma.

For pregnant women with opioid use disorder, the CDC and National Institute on Drug Abuse (NIDA) recommend medication with methadone or buprenorphine alongside therapy. Starting treatment early in pregnancy leads to significantly better outcomes for both mother and child.

The Bottom Line on Drinking and Cannabis in Pregnancy

Both alcohol and cannabis carry real risks during pregnancy. The safest choice is to avoid them entirely. Cannabis is more potent now than it was just a few years ago, and the cultural shift towards normalising its use makes honest, evidence-based conversation more urgent than ever.

Some questions about cannabis remain open, particularly around longer-term developmental outcomes. But the direction of research is consistent. Health professionals are not waiting for a complete picture before advising caution, and nor should expectant mothers.

Women who are pregnant, or planning a pregnancy, should speak openly with their healthcare provider about any substance use. Judgement has no place in that conversation. Sound information does.

Source: milwaukeeindependent